This invention relates to temperature control systems for rotating cylindrical drums containing hot material. More particularly, the invention relates to heat collector-sensors which can be placed outside a rotating drum and still allow effective control of the interior temperature thereof.
Several techniques for measuring temperatures in rotating drums are available. The most common is the use of thermocouples placed inside the rotating drum. Sometimes photocells or optical pyrometers are used to determine temperature in hot rotating drums.
In U.S. Pat. No. 3,896,556, a control system for a rotary coke cooler is described wherein signals from thermocouples in the drum control the amount of cooling liquid injected.
The use of thermocouples inside hot drums leads to problems because of the severe conditions to which the thermocouples are exposed, but prior to this invention, there was no effective way of controlling drum temperature using thermocouples positioned outside the drum.